CN117584537A

CN117584537A - Novel corrugated carton pit-following forming line pressing method

Info

Publication number: CN117584537A
Application number: CN202311725076.6A
Authority: CN
Inventors: 王若冰; 缪见; 刘海东; 祖珽; 王育放; 魏国宝
Original assignee: Henan Herui Packaging Co ltd
Current assignee: Henan Herui Packaging Co ltd
Priority date: 2023-12-15
Filing date: 2023-12-15
Publication date: 2024-02-23

Abstract

The invention discloses a novel corrugated case pit-following forming line pressing method, which comprises the steps of firstly designing a corrugated case sheet longitudinal forming indentation line into a U-shaped structure, and then changing the shape of a positioning knife on a case sticking machine into a shape matched with the case sheet indentation line; when the folding box is in operation, the lower surface of the adhesive tongue of the box piece is coated with adhesive, then enters the pre-folding part for pre-folding, the box piece moves forward, the folding surface is lifted up to 90 degrees by the folding guide rod, the U-shaped bottom of the indentation line on the box piece is lifted up synchronously to be in a vertical state, and is limited by the top positioning surface of the T-shaped positioning knife and the outer positioning wheel row, and then the folding surface is pressed downwards by the folding guide rod; when the folding angle is larger than 100 degrees, the pressed folding surface enters the lower part of the folding pinch roller, and under the combined action of the folding pinch roller and the folding guide rod, the folding surface is folded by 180 degrees at the folding part. The method eliminates the internal tension in the folding angle when the corrugated board is pressed, avoids the deflection of the folding angle, and fundamentally solves the problem of the industry difficulty of facial tissue bursting during folding.

Description

Novel corrugated carton pit-following forming line pressing method

Technical Field

The invention relates to a forming line pressing line of a corrugated case, in particular to a novel method for pressing lines of corrugated cases along pits.

Background

At present, almost all corrugated cartons are directly folded and formed by a production process, and a molded line pressing process is a forming basis of the corrugated cartons, and all cartons except a top-quality box are basically formed by directly folding and forming a corrugated paperboard after slotting or die cutting. But the quality problems of folding angle bursting or covering and off-line of the joint are very easy to occur in the process of sticking the box or nailing, especially the five-layer box with a thick pit has the bursting rate of at least 5-10% in the drying season, and the covering and off-line rates respectively reach 20-30%, which brings great economic loss to production enterprises.

The term "burst line" means: the four corners of each carton are folded together before the carton is operated on a carton gluing machine and the boxing is used, and in the folded state, two corners are folded in a 180-degree state, as shown in fig. 1a, the folded position after 180-degree folding is ideal, and the folded position is in the middle. However, the thickness of the corrugated board is thicker, generally 6-8mm, and the thickness can reach more than 10mm, so that the force of the facial tissue at the folded corner is particularly high during folding to form a sharp angle (the position indicated by an arrow in fig. 1 a), which easily causes the phenomenon that the facial tissue is broken at the position, and is called as a bursting wire in the industry. In actual production, the angle position achievement rate of the ideal state is less than 30%.

When the paper box is folded and formed, a standard opposite position line (an adhesive port forming line shown in fig. 10 c) is arranged, and when the folding angle cannot press the position of the trace line to accurately position and fold, if a corrugated bulge is arranged on one side in an included angle to support, the folding angle can deviate to the other side; the reason for this is that: the longitudinal forming crease lines on the corrugated case sheets adopted in the industry at present are all approximate plane crease lines, so that when the corrugated case sheets are folded, the inner paper layer and the outer paper layer are lengthened due to the influence of the thickness of the paper sheets, the upper bulge or the lower bulge appears, one side of the bulge can enable the corner tip of a folding angle to deviate to the other side, therefore, when 70% of products are formed, the folding angle is deviated to the upper side or the lower side to form a deviation angle (as shown in figures 1b and 1 c), and when the folding angle deviates upwards, the opposite line is far away from the positioning line, namely off-line is caused, as shown in figure 1b; when the folding angle is shifted downwards, the opposite opening line is caused to cross the positioning line, namely the cover line, as shown in fig. 1c; whether the folding angle is in the middle, is deviated upwards or downwards, and whether the folding angle is covered or is offline, the explosion phenomenon is easy to occur at the sharp angle, meanwhile, the opening and forming of the paper box are not square enough, the specification and the size of the paper box are not accurate, and the quality problem that the box is big at one end and small at the other end and cannot be used normally can be solved.

The current solution to the problem of bursting in the industry is to spray water to the paper box, but the consequence of spraying water is to directly reduce the compression resistance of the empty box of the paper box. The empty box compression resistance is a hard index of the paper box, so that the products in the box can not be damaged by compression, and the box can not be inverted or collapsed in the stacking and logistics processes. In order to solve the problem of reduction of the compression resistance index of the empty box caused by water spraying, only the physical index of corrugated paper can be increased, and thus the production cost of the corrugated paper box is necessarily greatly increased. However, the quality problems of line covering and off-line in the whole paper box production industry still have no effective solution until today if line bursting problems, empty box compression resistance problems and quality problems of line covering and off-line are all the time that customers must return goods.

Disclosure of Invention

The invention aims to provide a novel corrugated carton pit-following forming line pressing method, which can effectively solve the industrial problems of line explosion, line covering and off-line in the carton sticking or nailing process without spraying water to the carton, greatly reduce the production cost of the corrugated carton and improve the product qualification rate of the folding operation of the carton.

In order to achieve the above purpose, the present invention may adopt the following technical scheme:

the novel corrugated case pit-following forming line pressing method provided by the invention comprises the following steps:

s1, changing the shape and width of a longitudinal forming indentation line of a corrugated case sheet

The longitudinal crease lines on the corrugated case sheets are designed into a U-shaped structure, the bottom width of the longitudinal crease lines is slightly smaller than the sum of the thicknesses of two layers of case sheet paperboards, and the depth of the longitudinal crease lines is 80% of the thickness of a single layer of case sheet paperboards;

s2, changing a positioning knife on the box gluing machine

A T-shaped positioning cutter matched with the bottom width of the indentation line of the box piece is arranged in the length range of the pre-folded part of the box gluing machine, and a positioning wheel row is arranged at the outer side of the T-shaped positioning cutter;

s3, folding the forming line

The box gluing machine is coated with box gluing glue below a box piece, then the box gluing glue enters a pre-folding part to be pre-folded, a folding surface is lifted upwards by a folding guide rod to 90 degrees in the forward process of the box piece, at the moment, the U-shaped bottom of an indentation line on the box piece is lifted synchronously to be in a vertical state and is limited by a top positioning surface of a T-shaped positioning knife and an outer positioning wheel row, and then the folding surface is pressed downwards by the folding guide rod; when the folding angle is more than 100 degrees, the pressed folding surface enters the lower part of the folding pinch roller, and under the combined action of the folding pinch roller and the folding guide rod, the folding surface is folded by 180 degrees at the folding part, and the butt joint and the bonding are completed.

According to the normal process, after two box pieces synchronously carried out on the left side and the right side of the box gluing machine are in butt joint, the adhesive tongue with the box gluing glue is covered by the other box piece, and one paper box is glued; the paper box after bonding continues to run downwards under the limit of the folding guide rod and the folding pinch roller until folding, beating, pressing by a press machine and bundling are completed.

Because the longitudinal forming indentation line of the carton is designed into a U-shaped structure, the width of the bottom of the indentation line is close to the thickness of the two layers of carton sheet paperboards, the folding angle of the 180-degree folded carton sheet can be ensured to be a plane, the plane just meets the condition that no obvious tension exists at the folding angle of the two layers of carton sheet, and two right angles are respectively formed between the folding angle of the plane of the folded carton sheet and the upper surface and the lower surface of the folded carton sheet.

Compared with the traditional sharp corner-shaped folding angle, the folding angle formed by the line pressing method can change one 180-degree folding angle into two 90-degree folding angles, so that the extremely high tension of the facial tissue in the folded state is eliminated, and the line explosion phenomenon is avoided. When the folding device is used in actual production, the qualification rate of the square folding angle is more than 99%, so that the qualification rate of a line pressing product is greatly improved, and the production cost is reduced. Meanwhile, the creasing lines on the corrugated case sheet are changed into wide pressing lines, and the corrugated case sheet is not supported by corrugated bulges in folding angles during folding, so that the phenomenon of deviation of opposite positions is avoided, and the quality problems of cover lines and off-line are effectively avoided.

The width of the top positioning surface of the T-shaped positioning knife designed by the invention is synchronously reduced along with the continuous increase of the folding angle of the box piece, and the folding angle is completely disappeared when the folding angle is more than 130 degrees before the complete butt joint is completed.

The invention has the advantages that:

1. after the indentation lines on the corrugated case sheet are changed into wide line pressing lines, the internal tension in the folding angle is eliminated, and the deflection of the folding angle is avoided; meanwhile, the original 180-degree folding angle is changed into two 90-degree folding angles, so that the influence of tension on the facial tissues is completely eliminated, and the problem of facial tissue bursting during folding is fundamentally solved.

2. Because the wide pressing line has a certain positioning effect, the supporting caused by the corrugated bulges in the included angles during folding can not be avoided, and the quality problems of covering lines and off-line are fundamentally eliminated.

3. The line pressing on the corrugated case sheet is changed into a wide line pressing, so that the total width of the indentation line is reduced by nearly 50% compared with the traditional indentation while the tension in the folding angle is effectively eliminated, and the blank case pressure resistance of the paper case is greatly improved.

4. The wide pressing line designed by the invention covers the width of the notch of the box slice shake cover, so that the problem that the notch at the folded corner is rotten during folding when the box is stuck can be effectively avoided.

Drawings

Fig. 1a to fig. 1c are illustrations of existing folding angles in the industry.

Fig. 2 is a corrugated box sheet to be folded in the embodiment.

Fig. 3 is a schematic drawing of a corrugated box sheet in an embodiment.

Fig. 3a is a line graph obtained according to current industry standards.

Fig. 4 is a diagram of the structure of an indentation pattern employed in the present invention.

Fig. 5 is a diagram of the structure of the T-shaped positioning knife according to the present invention.

Fig. 6 is a folding state diagram during a box gluing machine forming operation.

Fig. 7 is a relative position diagram of the folding box piece and the T-shaped positioning knife when aligned.

Fig. 8 is a state diagram between the folding surface and the present folding portion during folding.

Fig. 9 is a shape of a square folding angle after the folding operation is completed.

Fig. 10 a-10 d are flowcharts of the operation of the box sheet.

Fig. 11 is a transverse cross-sectional view of fig. 10 d.

Detailed Description

The present invention will be described in more detail below by way of specific examples in conjunction with the accompanying drawings so as to facilitate understanding by those skilled in the art.

Taking the corrugated box sheet 100 (fig. 2) of the five-layer box with thick pits as an example, the thickness of the box sheet cardboard is 7mm.

The novel corrugated case pit-following forming line pressing method comprises the following steps:

first, changing the shape and width of the crease lines on the corrugated board

Firstly, modifying an indentation die on a printing machine, and changing a traditional V-shaped indentation die on the printing machine into an indentation die with a U-shaped structure for pressing a longitudinal molding indentation line of a corrugated case sheet;

after being creased, the creasing line on the corrugated case sheet 100 is formed into a creasing line with a bottom width of 10mm, an upper opening (mouth transition width) of 15mm and a bottom thickness of 2mm, and is in an approximate U-shaped structure as shown in fig. 3;

compared with the invention, according to the current industry standard, the indentation die is of a V-shaped structure, the shape of an indentation line is similar to that of a V-shaped structure as shown in figure 3a, the bottom width is 2mm, and the upper opening width is 30mm.

In actual production, the embossing die is an embossing wheel 200 mounted on a working shaft, as shown in fig. 4, and in operation, the embossing wheel 200 rolls on the case sheet 100 to form embossing lines. Typically, the bottom width of the formed score line should be slightly less than the sum of the thicknesses of the two ply linerboards and the depth 80% of the thickness of the single ply linerboards.

The width of the bottom of the wide creasing line designed by the invention is 10mm, but the total width is only 15mm, and compared with the traditional creasing line with the bottom width of 2mm and the total width of up to 30mm, the wide creasing line reduces the corrugated breaking rate by 50 percent, and greatly improves the compression resistance of an empty box.

Second step, changing the positioning knife on the box sticking machine

The thin positioning knife for the original box gluing machine is improved, as shown in fig. 5, the width of the paper feeding end of the top positioning surface 1.1 of the T-shaped positioning knife 5 is matched with the bottom width of the indentation line of the box piece (9 mm, a pre-folding section), after entering the folding section, the width is gradually reduced from front to back, and the folding angle is larger than or equal to 130 degrees and is reduced to zero;

thirdly, folding operation in the molding operation process of the box gluing machine:

firstly, a T-shaped positioning knife 1 is arranged in the length range of a pre-folded part of the box gluing machine, as shown in fig. 6, the top positioning surface of the T-shaped positioning knife 1 is at the full height of the pre-folded part of the box gluing machine, and after entering the pre-folded part, the top positioning surface is synchronously reduced along with the continuous increase of the folding angle of an upper folding box piece; after the folding angle is greater than 130 degrees, the top width of the T-shaped knife is completely disappeared (becomes thin).

Positioning wheels 2 are arranged on the outer side of the T-shaped positioning knife 1, and the positioning wheels 2 are arranged at intervals along the length of the T-shaped positioning knife 1 to form positioning wheel rows;

the number of the folding pinch rollers 3 is several, the folding pinch rollers are arranged at intervals with the outer positioning wheels 2, the installation positions of the folding pinch rollers are arranged after the folding angle of the box sheet is more than 100 degrees, and the elevation angles of the folding pinch rollers are synchronously adapted with the folding angle of the box sheet; the flat pressing wheel 4 is positioned at the tail part of the T-shaped positioning knife 1, and is matched with the outer positioning wheel 2 to form a folding angle after the box piece is folded 180 degrees;

when in alignment, the inner side of the bottom of the folding piece indentation line of the box piece is aligned with the lower corner line (positioning surface 1.1) of the top outer vertical surface of the T-shaped positioning knife (as shown in figure 7); during operation, the paper feeding table feeds out the box piece, the glue spreader with the pre-folding part at the left side coats glue on the lower surface of the moving box piece glue tongue, the box piece 100 continues to move forward, the folding surface is gradually lifted up by the folding guide rod 5 to 90 degrees, and then is pressed down by the folding guide rod 5 (the state between the folding surface and the folding part of the box piece is shown as figure 8); the folding box piece continues to move forward, and the folding guide rod 5 is fully pressed on the opposite joint to press the box piece joint so as to prevent the folding box piece from bouncing; then the folding wheel 3 and the folding guide rod 5 are matched to complete 180-degree folding, and finally the flat wheel 4 and the folding guide rod 5 are pressed together to complete bonding, and the folded angle after bonding is in a square structure as shown in figure 9.

The left folding mechanism and the right folding mechanism of the box gluing machine are mirror images, the box sheets are folded by the left folding sheet and the right folding sheet at the same time, the sticking tongue on the left side is arranged below when the box is opposite, and the right sheet is pressed on the left side;

The workflow of the box is as shown in fig. 10 a-10 d:

FIG. 10a shows a box piece before box sticking, FIG. 10b shows a box piece structure in the box sticking process, FIG. 10c shows a box piece structure after box sticking is completed, and FIG. 10d shows a box after packaging; fig. 11 is a cross-sectional structure of the formed case, and it can be seen from the figure that four corners of the case are all plane turns, so that the case is not easy to burst and is more regular.

The inventor of the application starts from the outline of the appearance of the paper box aiming at the historical problems and prejudices which always puzzle the industry, changes each 90-degree right angle of the original formed paper box into an obtuse angle formed by connecting two 45-degree angles, can change the folding of the 180-degree angle into the folding of the 90-degree angle when the paper box is folded on a box gluing machine, completely eliminates the internal tension in an included angle, and when the paper is folded, the paper is not influenced by the tension any more, thereby fundamentally solving the technical problem of the paper bursting wire, and simultaneously effectively solving the technical problems of the cover wire and the off-line which are the most difficult to solve in the past and the quality problem of the cut rotten angle.

The invention adopts a relatively simple method, does not need to increase equipment or change working procedures, greatly improves the qualification rate of finished products of the folding working procedures and reduces the production cost of the paper boxes on the premise of ensuring the compression resistance of the empty paper boxes.

It should be noted that all the data in the embodiments of the present invention are parameters set for corrugated boards with a thickness of 7mm, and if corrugated boards with other thicknesses are used, the parameters can be adjusted accordingly.

Claims

1. A novel corrugated case is along hole shaping line pressing method, characterized by that:

s2, changing a positioning knife on the box gluing machine

s3, folding the forming line

The box gluing machine is coated with box gluing glue below the gluing tongue of the box piece and then enters the pre-folding part to be pre-folded, in the forward process of the box piece, the folding surface is lifted upwards by the folding guide rod until 90 degrees, at the moment, the U-shaped bottom of the indentation line on the box piece is lifted synchronously to be in a vertical state and is limited by the top positioning surface and the outer positioning wheel row of the T-shaped positioning knife, then the folding surface is pressed downwards by the folding guide rod, at the moment, the pressed folding surface enters the lower part of the folding pinch roller, and under the combined action of the folding pinch roller and the folding guide rod, the folding surface is folded by 180 degrees at the folding part.

2. The novel corrugated case pit-following forming line pressing method according to claim 1, wherein the method comprises the following steps: the width of the top locating surface of the T-shaped locating knife synchronously decreases along with the increasing of the folding angle of the box piece.